Understood, but that generates additional side questions:
What is the technical reason(s) for a broadcaster to actively pursue and specify a 14Hz resonance?
We are not broadcasters. Is a 14Hz resonance, which may suite the specific needs of a broadcaster (and what might those be), the same thing we want in a home system?
My original question remains unanswered.
Ray K
Resonance should be between the warp region and the audio region, so 10-15 Hz,
regardless of the application.
Happ, L., and Karlov, F. “Record Warps and System Playback Performance"
http://www.laudioexperience.fr/wp-c...-Resonances-in-Turntables-AN17-233-1977-1.pdf
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Note that the critical frequencies are different for vertical and horizontal resonance. The horizontal resonance can be between the 0.555 Hz record eccentricity and the lowest bass note in music (20-40 Hz) and the vertical between the warp frequencies of 3-6 Hz to the lowest audio frequency in the vertical music content (about 100 Hz).
As per Rayma the 4-10Hz region should be avoided if at all possible for highest fidelity as the ear is most sensitive to FM artifacts in this band. So yes the BBC did have a good reason for this. At the other extreme the Ortofon wand for the SME 3009 series 3 has a 13Hz resonance off a 4.5g total effective mass with a high compliance setup.
As to which is the right approach I don't know. A cartridge with a compliance of around 10cu on an average modern arm such as an RB300 also has a similar resonance so an ortofon DJ cart on that should also do the job. I have not yet tried that combo but know that LD has had very good results.
As to which is the right approach I don't know. A cartridge with a compliance of around 10cu on an average modern arm such as an RB300 also has a similar resonance so an ortofon DJ cart on that should also do the job. I have not yet tried that combo but know that LD has had very good results.
To cut a long story short, the answer lies in making the best use of whatever damping there is available. Higher resonant f has a shorter settle time for any given damping. Settle time equates to pitch stability in response to a stimulus that causes the headshell to move.
Performance isn't really about resonant f, that's another half-truth. Obviously, it pays to avoid the stimulus f of warp etc, which most systems do by about an octave or so and so are about the same really. It's all about about damping, which mostly comes from cartridge suspension elastomer. And since the same elastomer provides spring and damping, stiff suspensions generally have more damping.
Put all this together, and 14Hz with a low Q is better than say 8 Hz with a high Q, in terms of settle time and hence pitch stability in audible terms.
This is not well covered from back in the day in terms of papers etc, but there's some stuff from Leigh Phoenix on Boston Audio Society which explains it well from the early 70s.
HTH!
LD
Performance isn't really about resonant f, that's another half-truth. Obviously, it pays to avoid the stimulus f of warp etc, which most systems do by about an octave or so and so are about the same really. It's all about about damping, which mostly comes from cartridge suspension elastomer. And since the same elastomer provides spring and damping, stiff suspensions generally have more damping.
Put all this together, and 14Hz with a low Q is better than say 8 Hz with a high Q, in terms of settle time and hence pitch stability in audible terms.
This is not well covered from back in the day in terms of papers etc, but there's some stuff from Leigh Phoenix on Boston Audio Society which explains it well from the early 70s.
HTH!
LD
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Yes. I wrote a simulator a few years back......or was it a dream? Most rigs are somewhat underdamped to various degrees, and generally benefit from a helping hand from some external damping IME/IMO.
The main benefit is to pitch stability, same for mono or stereo records of course. But the main stimulus, IMO, is momentary variation in stylus-groove contact friction (via skate force) which does wrap into best stylus profile for mono vinyl composition so I reckon.
As to 0.5 x 1mil elliptical, at least there's hope that the contact location height and base clearance will be good for mono recordings. But 0.5mil minor radius might be the issue IMO, since I reckon that defines contact profile. Good to know though, and I've never tried it, worth a shot I think.
I have a lot of monos. It was a 1953 mono record that first bowled me over in terms of overall fidelity, Della Casa/Bohm Four Last Songs Decca 1953. And that's where I became fascinated by how any such thing was even possible from an early 50s recording and production system. Still amazing. 10 years later I'm still digging away trying to understand the fine points of why and how vinyl recording/playback can work so well.
LD
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I was looking for the Leigh Phoenix article on tonearm/cartridge damping from 1975, and found it still available here:
It starts around page 23, don't be fooled by an earlier letter on the topic in the same newsletter.
http://www.bostonaudiosociety.org/pdf/bass/BASS-03-04-7501b.pdf
By coincidence, starting on page 14 or so is an article about stylus shape and groove dimensions, base radius, cutter shape etc. also covering and mostly confirming our discussion here. There's a few things I'd take issue with, but worth a read on topic for this thread.
LD
It starts around page 23, don't be fooled by an earlier letter on the topic in the same newsletter.
http://www.bostonaudiosociety.org/pdf/bass/BASS-03-04-7501b.pdf
By coincidence, starting on page 14 or so is an article about stylus shape and groove dimensions, base radius, cutter shape etc. also covering and mostly confirming our discussion here. There's a few things I'd take issue with, but worth a read on topic for this thread.
LD
Thank you for the link. Will have a read tonight if my brain holds out until then...
My 'wow' moment with mono was a DG recording I got in an ebay lot, so I think it cost me 10p. A simple recording of Tenor voice and piano, but I was bowled over, I do however also have some that sound awful such as a 3 disk ace of clubs issue of Handel's Messiah. Intriguingly it was originally a 4 disk set so one day will hunt out the originals. The distortion on the choral fortes is huge, but not sure if it was my setup, a damaged record or just a rare duffer from Decca.
Found an ortofon concorde nightlub 2 for £27 so will order that so I have a 0.5x1 to try out.
My 'wow' moment with mono was a DG recording I got in an ebay lot, so I think it cost me 10p. A simple recording of Tenor voice and piano, but I was bowled over, I do however also have some that sound awful such as a 3 disk ace of clubs issue of Handel's Messiah. Intriguingly it was originally a 4 disk set so one day will hunt out the originals. The distortion on the choral fortes is huge, but not sure if it was my setup, a damaged record or just a rare duffer from Decca.
Found an ortofon concorde nightlub 2 for £27 so will order that so I have a 0.5x1 to try out.
Had a read of the Pheonix article and kept thinking I should revist the Lipshitz article where he talks about 25% damping at cartridge end and 75% at bearing for the warp case, which I assume is a lot less of an issue in mono?
But the think I am really struggling with getting my head around at the moment is the sources of damage in mono. For stereo it's always mistracking, but for that to be an issue surely you would be talking about skipping out the groove completely*? So other than dirt and muck you only have the cases of a worn stylus gouging lumps out? Or am I missing something obvious?
* and in the case of say a classic mono ortofon you'd have to lift the whole 30g cart up which is not going to happen!
But the think I am really struggling with getting my head around at the moment is the sources of damage in mono. For stereo it's always mistracking, but for that to be an issue surely you would be talking about skipping out the groove completely*? So other than dirt and muck you only have the cases of a worn stylus gouging lumps out? Or am I missing something obvious?
* and in the case of say a classic mono ortofon you'd have to lift the whole 30g cart up which is not going to happen!
I've heard some good things about the Hana SL Mono, and Herb Reichert, a friend who also happens to review gear for Stereophile likes it a lot.
I am familiar with the HANA SL and EL, stereo cartridges both of which are surprisingly good cartridges at their price points, and will not be embarrassed by much more expensive competition.
I don't get the mono thing (I grew up in the stereo era) but have slightly older friends who apparently do.
I am familiar with the HANA SL and EL, stereo cartridges both of which are surprisingly good cartridges at their price points, and will not be embarrassed by much more expensive competition.
I don't get the mono thing (I grew up in the stereo era) but have slightly older friends who apparently do.
Will do. It's the data I am after. Luckily no styrene in UK but it's a brave man who plays styrene with a line contact according to internet lore.
Attached is the picture that indirectly caused me to start this thread. I'd been aligning my stylus and it was pointed out that the strand attached to the diamond 'might' be a vinyl shaving as I had been playing a 50s mono with it. Intrigued I was...
Attached is the picture that indirectly caused me to start this thread. I'd been aligning my stylus and it was pointed out that the strand attached to the diamond 'might' be a vinyl shaving as I had been playing a 50s mono with it. Intrigued I was...
Attachments
Hi Bill, that strand could be. But it's the small bundle of fluff just above the back straight edge of the stylus that caught my attention. I examined such debris under high res microscope and it looks like a bundle of black strands of a single substance. I took it to be shavings.
Have also seen very long thin strands almost hair like 1or 2 cm long.
LD
Have also seen very long thin strands almost hair like 1or 2 cm long.
LD
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